Objectives : The present study was designed to evaluate the protective effect of Allium tuberosum (AT) extract on atherosclerosis in LDL receptor knockout (LDLr KO) mouse fed western diet.Methods : The AT was extracted 70% ethanol. The experimental groups were divided with four groups of LDLr KO mice, one group fed a normal diet and the others fed a Western diets for 8weeks. Two Western diet groups were orally administered AT extract at dosage of 100 and 300 mg/kg body weight. The body weight and food intake were measured every day. We measured levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglyceride (TG), total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoprotein (LDL), and Glucose in serum. Also, effect of AT extract performed using H&E staining.Results : The AT treatment groups showed decrease in body weight and food efficiency in comparison with control group. Blood biochemistry parameters such as TG, TC, LDL, and glucose levels were increased in control group, while AT treatment groups were reduced. Also, the increased levels of ALT and AST were improved by AT extract. We confirmed that the weights of liver, kidney, subcutaneous fat, epididymal fat, kidney leaf fat, and intraabdominal fat were change in LDLr KO mice treated AT extract. In addition, histopathological changes in liver and aorta were similar to normal group.Conclusions : Based on these results, the AT extract is considered to make prevention of atherosclerosis through reduction and functional improvement of the liver and vascular endothelial cells in the body fat accumulation and lipid content in LDLr ko mouse model.